SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f2460d08fec1d5002a015a122ccb0915cfd3b540411025cf52eb970062f32963' 
  AND token = '5g7hp2fN230x1nt6VuZ1s84ZNp5hpqAblH+Pjbk3cus=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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