SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c19a2b1303af0aea76530ba790b06ba1ece41b5051cd5fb8569929137a74a1a6' 
  AND token = 'oZFGyR6IXos+YD/OBqUYF4QTIydPrUwOqpBx8lomGI8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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