SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1842bb89fb720b83897bc87cadd6c6070a1e9973b81f9264ef9667a6182e596d' 
  AND token = '85ZRxX+cqpzJV/4swkGGwcHg/YwY/BO2j95dXvPnJJg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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