SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '289313f44e92faf0387790f025a9958b7743513a129238f70376e0a86cfa7322' 
  AND token = 'jFtNkZ68bOXkoUKS7yBIy3/wHFXqzpCEWqP7mBnTQqI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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