SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7e571f459ee25aac9329c62d7ae1cf49d23c08fe30d766b49ac00fbff3040bdf' 
  AND token = 'kZ6SvByULiAeA7aIQcbJR2NvnmgmFopCrj1bx1skDt0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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