SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'da858a404267a4d24a5a69fe932f5f6d9b5d04dbb19df581192dbc24661664d2' 
  AND token = '/aHtuCqyzxVMq4QYGOVJ1GIr7qMwuFz1q2ktK7R43zQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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