SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '173e26feb52e28044eb8effded2131c2c5779c7911b3fd896a67f32395a117bf' 
  AND token = 'x6tLXOmdW5hSuJN+t6aY5cDQfgvz8CgR1XXBqgc6Pso=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

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