SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dca986fb2f0a8f4f47f4e4d3bc6628040e8e8f5252977959b791620b352247ef' 
  AND token = 'iRgeqWZV55TYbUNgylJpnHPyva+peX3+rsKpU4tLF9U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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