SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c8a822471cb4d01631e26005e77777b03bba78dbf706927547df03357be6af1d' 
  AND token = 'w4Kaw3bScqRB7GiRZQZmVRilxqeVs0yXwlkbkzhvm+8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00050

JSON explain

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