SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bc45143948eb238ca63e1f36929db8dcdc9974b923df378fc1f1d35ff6a8723a' 
  AND token = 'DVB7+Php4ttvKijsyhv6UmawEomaPLWFIiR6gz9Pgjw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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