SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6f0881d088ac3c2802e2a23b18ffa250a401cccd66c13b85144fd77fa68700eb' 
  AND token = 'T2HgJK8MZIiKjiHG9PPncFO9CT191FCGnjFm6ARKEw8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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