SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3426b587f21b5fd049ad3191ec031c8d69f3121e62bc362f5d3c3781c142097e' 
  AND token = '45uiAsN2gIgKk62H8AeYk/WWvVWgNS9jTvnXEARkCWE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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