SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6f370168c53abeb592da1820dbece31abe71c131485658122f18590a48025e04' 
  AND token = 'j5Rp/hRwGC50WMIRkTiWfVShhHHzCR56pVdnjyydgaY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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