SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f024969d79f20dc43854e327dba761760dae6fc286cc1b669c5b9987cd907e3c' 
  AND token = 'Cosu/IispYeLR4K83tGo9gj4OFGD38H8yLBDvYUHjrw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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