SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b70a09a0921f0fb333c58e28d1dff2de19d084ddc98c27566499be6ff7ff9ee2' 
  AND token = 'KtKGBgYeDAK/wyKAoP8ad44wbU0UFzqDq7NPFqkmKd8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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