SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '6d01cfaed252061046dcc0bc635c3c1694dfde091087f30dda6b45ac46dda80c' 
  AND token = 'M9J6V98amz3uMqQMMSINjvRRY/fhPDuADd77BPgdwGg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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