SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6adf89877b34db26972dd9a78e63a663618b8c8468b3c6252dfdc6a956b0d1bb' 
  AND token = '4vhvHfomXoewpPuEY2ZVLalWH8oq8lqz1BSLKK6Gn8M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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