SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9171f55ab8d1b0cb3f9cdae84321d794bf57eb43934de29b6fcb3223d893925e' 
  AND token = 'tPUc7Lh2yod2iToYSPJVCk9XhpU4MpvyqRsA7Le1SQU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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