SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7da8f2533d5e650fcefaabcdcdff80b7dbb4a963efa85299d7330ab16a4f72e8' 
  AND token = 'usZzqbtUZIc9fL7TgyDfVf8aFHxGSc56/KZr0vR+N+4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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