SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '231d63a0244255f4d67588e8ca965c58fb2918d89cf7f6d5d7fa71e0edb6b5ef' 
  AND token = 'rWtbNh2wD0NmGTafIJcr//L6/f4qsLAfFuoK2SYIZME=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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