SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a1acd509771cfb50f0171db9219017b3ce2f41a6156931b620927e5ccf32c6b0' 
  AND token = 'JpcIHESSC2C7g2Mepk94/fgZX4iCYXAtmdjhH/RLlL0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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