SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4c775febe943a2fdb8f2522b987b3a5c4d9a6381f34eda4d957265fae7316e0e' 
  AND token = 'KRCY7hjh3+eMpknaHJPiNl8x+v0lgiypZEUU/172DWs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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