SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '44d824cfd97858a03916bcefb92500ba960f25434abd6e457ddb12121d6d1965' 
  AND token = 'BmqilNYuWuhSucLQYs2Sx2usthMj2JOidK6jZrqO9yg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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