SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '966475cbc6ee09648635ab848d9135bab1d9b4520c18608afffdd9b2173e3a81' 
  AND token = 'Pc6LYuXWqVaFirUfJZm55mG4VSzcZ1AK1ft5F1rjWCk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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