SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '049c3154e3946f176aeac916bf3361fc55bce0d1541de88ae534a9df2cdc7c79' 
  AND token = '7iffp7S4Psb8Hs0uDckedvVNyANBa49yBxcY0NjrSlo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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