SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0421469ead9c5ad0915a866b3dab35bf67bfa48510f2ad71cc281d8748139f86' 
  AND token = 'mtd10r5xYWwvCQRXf0QuS69FKtBjCxk+msvVPLh4iIc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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