SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'b81c4c537d86b359e94c0c1b0890c58bc8fd5f8627fd58e29c487b25998d87e1' 
  AND token = '2PQKjFz7pQkTH3FFwO669u2wC2T3YJU/njPfC/9WdNY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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