SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9d960b4d6be79363e23b858c01a68aa493a5131a94067a9ec91ac815fe07b22d' 
  AND token = 'SUHvCJbRtzqttBr6XGIVl+6AJjGRRjVS1cZmwprqwQk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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