SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1aacd4f6243c9ffd61fec302bdefa2dd8489dc463bb1f3ddcb397059e7c48b55' 
  AND token = 'wnqZ/L1HpIYl/swMbjD+tFvnCX5vIrwHXT/j4Slb/Fo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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