SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4f8f88f55362491c95b86ffbb5de1145bd9b23d890638b645e28f1600f275e5e' 
  AND token = 'Q7Iq3cXTTcrNTAx/bIAcKREKoRKEIA9+HARyx2SSNIc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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