SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'edf402d73f91b5c4c2ce67ed64417ee8912a2bc32defbe57c63ddc4de327f0f9' 
  AND token = 'D5DMHTJCM4aDj8xtrRe65YlDz3JvFdrIY0/lJPe4VQQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}