SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '163754d864802611d96f6bae18db94f42188db341035768c70928f8eade47e35' 
  AND token = 'whpsjIm3huLiX8WIb8qs92mkzX2NVBBDfeSSUvm+8ek=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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