SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '848d5b18db2bcdfee165ebb6afe49108ec6395b57174dd3193aa928dfb231feb' 
  AND token = 'irT8rOH+VOXge45ii0uIRt/KQ+oBbqcfyyL6LISoJW8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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