SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ad09bbc14de7c560869697218511ef2d5faf86a0403008ada45e78e43d7cce03' 
  AND token = 'sFBiebwXBtSMA+0oEJu/x4LVZALUExpHtUQZlbTUHUA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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