SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '12f1d38e9ddd5727a8efa85b4edecfadaa1cb816e9c6f7aadd14cf2ebe9af30c' 
  AND token = 'biSCAQPTEWsbTDZXStzbZN8g6LAw1ON9Sq+x/mS4PeQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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