SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '96c4661d7efd84056c70aeed2a7790f51c832214456161edfe6ddb74730191ae' 
  AND token = 'lJEMh/8VkbbR9Qb/m66t9/kYukxZ7psSuuurD874/tU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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