SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '64e4ac17863db2eb0d2f14687004843a2ccf056fc09a598f8c99faf76f3bc448' 
  AND token = 'az2oQaTZPLYmt+biwrJnrKt5CzwqK4DMPkOV7GXBoek=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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