SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6657cd83a450605f1aa419f2902c63e3e730d3591a6666d76ff0109ace9467ba' 
  AND token = 'dI+lL2x002TUvFZuMqDn3HgXpENUKILuATR1nSXyzsQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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