SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a6baf5244b495f39a4639caf72c217b611d50b671a36f26f9222aa64495a7965' 
  AND token = 'ZuxcKkAC7XIqSogKD2s0lD6hoz6y+9B+e+Gw4UIkwQ8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00080

JSON explain

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