SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b1ec5bd1d7914a2ba906b114259337904419220369df0bfad52eb16953bdac82' 
  AND token = 'EX+Fok+JxBUaXBonZKCS/B/EVDa45jPGIJOT3ukxhN0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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