SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '62a5d1cb073968affac872b87cffb2ad68372190105a5a671faffb62dff2a776' 
  AND token = 'DC7rkIwQzYbLQLSlsbqdq35/zKsGM9ePy/2Hrq1pVmE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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