SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '9b9999237c0b010d926b39c0c20df19c6b17e5857a4dcf765e39da2fd1d0e646' 
  AND token = 'umZbEpYJsXNvoOpForUB0go/cpngnFJDDMxCyjWr8XE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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