SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bc11e81b6669be3ce930357843c6bc2b298ddaf66eed651b0ca8388599fad747' 
  AND token = 'bFshEgF04ioAHhyLB/PvRg6AHfgzD11Kxf5E+Z/Pmdg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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