SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '776ab63ff8003113b62bf2ed85ad56a1c40c220bb5d01ad9bca7721265826e7c' 
  AND token = 'e7uWpkCIQEVHqqpSvEDXzy5Hxd02YqKaENIosaAKLnk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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