SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '73fe2d3adc323a81a93d1b70a058efad15cab139ee24e2da245d98ddb2471ee3' 
  AND token = 'Qy0X440ChiQM+/jOxyykF3jrLMxhtU0NfFj9RpOrIeQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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