SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c85ac6e4b0dedffc325221b5a99232f12b6c6dc84504cf941746720ec250a190' 
  AND token = 'ih5BHEXvCIpM91fSBVKXZ92A3kLF+zqDHglYeh+w+SI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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