SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ec4fdb85b0039e1e4476bf34a48f72d1c05acf02c6169d301b390504430dac3a' 
  AND token = '7WbyC4oWsPV1tfwemRFehYjl5vE6E2SbCRIQqoBIU/A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}