SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'aebc321e93c6e0cfe4411fcd408c347356774843c3fef29a0b641bc801d7af35' 
  AND token = '1deaC81qc3xo9lGpDboEFjr16HMzZ+WSSt/nSMr2va4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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