SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bd57db242388f3ac6e45c36b0f64c2eba261ac1b29c492c1b044a46e29547b2f' 
  AND token = '7bREt3PAzN9CgmFuZ4F78oar4MptNzCxyahpMbCBDt4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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