SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f58fd961486a005bb1b95794d4a4b1a4977c258b4f8c030758ce6ad54cc4d383' 
  AND token = 'CKPBmr/PkDJ+82oB94UDlk8BAjvHDBEftM/KGhbh0zo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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