SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '00853ae9a9363b7e11ee66024df66e8795c0677cc5df698ff1d9be031b6879c1' 
  AND token = 'r/hS9T4JlrK4PwEKlHz/CcKLimqOgBdPZa+dR6rgNvM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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