SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '542ad5e78c649f2533e8698d55f89eb982d1a24489fb95b0c4628fcaea5139bb' 
  AND token = 'v/kxWFuZ83RnngW/IsfVzhGr81rCVd0ZO6qxUNR8+Kw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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