SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '83a50d9886c66005a7d1bfdbbed385871ae09a0a78fdbb24726b11ac5a0b14f1' 
  AND token = 'nKDqXNvt3lr81oAbR0iU8DpNGR1Fxl8Up9/NtmUYkqA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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