SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '25be2161d63d1bd1d450a0df50e08f383de9609bc44e8b61281b876609fcce4b' 
  AND token = 'kO8XSyRnfBMKaMpmoxLTcbwbvMhK499sfMlbYRKw2AY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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