SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'b5294755f3250be01910aa1479b5f7087685ac699ab0d8f2ad95e9f85fa91491' 
  AND token = 'sTpqnYQlZnUeBoqOzN2ZowS/1T6U9VX9rCxfv3jiyO0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}